Representative gels and deduced genetic pathways for case G33. Gel for D17S786 shows homogeneous LOH at 17p for all dysplastic and invasive foci (T2, T4, T5, T7, T10, T12, and T14). Ordinary epithelium (T13 and T24) retained all alleles tested. Divergent LOH at 18q and 6q is shown with two different markers (D18S487 and D18S46 for 18q, and D6S264 and D6S473 for 6q) to clarify the true nature of the heterogeneous patterns and to exclude spurious PCR reactions. *, Normal alleles; arrows, divergent patterns of allelic losses detected at 18q (D18S487, and D18S46) in some of the dysplastic foci (18q-β at T5, T7, T20) and all of the invasive foci (18q-α); arrowheads, LOH at 6q detected only in some of the dysplastic foci (T2, T4, T5, and T7); N, normal control DNA; T#, microdissected foci.